According to New York Times, Mr. Lund said in a telephone interview that the new results were based on more rigorous testing. For the first time, the institute conducted crash simulations, he said. "The big thing that's happened here is we've raised the bar."

According to the institute, a safe restraint must be close enough to a passenger's head so that the device cradles the head during a collision and prevents it from accelerating at a different rate than the torso. When the head and torso move at different rates, the neck is strained and whiplash can result.